Ruby Issue Tracking System

09/30/2026

06:34 AM Ruby Bug #22393 (Closed): Backport bf937bfa16767a4dd857ee16f4f18df1bae4d5ca - Fix memory leak on compile error in a later branch of an alternation

please backport this to Ruby 4! Ruby 3 is unaffected.
Commit: bf937bfa16767a4dd857ee16f4f18df1bae4d5ca
PR https://github.com/ruby/ruby/pull/19026
Original ticket: 22384 sethuarun (Sethupathi Arunachalam)

09/25/2026

05:21 AM Ruby Bug #22384: Regexp compile error in the 2nd+ branch of a top-level alternation leaks the parse tree (regression from #13332, Ruby 4.0)

Fix and regression test: https://github.com/ruby/ruby/pull/19026. Verified on a build of v4.0.7 with the patch: Regexp.new("a|b(c") rescue nil goes from 134 B leaked per compile to 0, and 2M calls of /(?:a|b)c(d)/.to_s from +250 MB RSS t... sethuarun (Sethupathi Arunachalam)

04:39 AM Ruby Bug #22384 (Closed): Regexp compile error in the 2nd+ branch of a top-level alternation leaks the parse tree (regression from #13332, Ruby 4.0)

**Affects:** ruby 4.0.6 and 4.0.7 (official docker images and a jemalloc-linked build), master (commit still present). **Not affected:** 3.4.6.
**Repro (plain Ruby, no extensions):**
```ruby
def rss_kb = File.read('/proc/self/status... sethuarun (Sethupathi Arunachalam)